


Unnatural and Abnormal

by nowherenew



Series: Demon!Stiles [1]
Category: Supernatural, Teen Wolf (TV)
Genre: Alternate Universe, Angst, Demon!Stiles, Demonic Possession, M/M, Mild Gore, Mind Games, Non-Explicit Sex, Vaguely Referenced Sex, Violence
Language: English
Status: Completed
Published: 2012-07-21
Updated: 2012-07-21
Packaged: 2017-11-10 10:39:47
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 1,327
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/465349
Author URL: https://archiveofourown.org/users/nowherenew/pseuds/nowherenew
Summary: <blockquote class="userstuff">
              <p>Derek finds out why Stiles hasn't been acting like himself lately.</p>
            </blockquote>





	Unnatural and Abnormal

**Author's Note:**

> Spoilers for the season 1 finale, I suppose. Also, beware: demon!Stiles is extremely violent. Not for the faint of heart, though I suppose since it's my first time writing extremely violent things, it's not so bad for you seasoned gore-watchers/gore-readers. Enjoy!

Stiles is not a graceful man. No, that's not right. Stiles _wasn't_ a graceful man. He could practically have been defined by klutziness; he was always jerking around, making little spastic movements or overt hand gestures. He used to scramble for cover, or stagger when he was wounded. Stiles hated fighting.

Now, he _glides_ through battle. He darts to safety like a cat, escaping hunter bullets like they're NERF projectiles. He can tell when something is about to attack him. He doesn't heal like a werewolf, but Derek has seen him sustain a stab wound that was gone by the next day. He's killed two men in the last month. It's unnatural. It's not like Stiles.

Stiles is not a suave man. Well, he didn't _use_ to be a suave man. He used to talk too much in bed. It was awkward, but Derek didn't mind much. Stiles was always newly exhilarated by touching Derek, or by being touched. He snorted, laughed and squeaked when having sex, and he'd latch himself to Derek's chest like an infant when they were done. Stiles loved cuddling.

Now, he _uses_ Derek. His touches are even more practiced and effective than Kate's were. He unabashedly drags his mouth along Derek's neck and bites hard enough to draw blood. He does things to Derek that he'd previously sworn he didn't feel comfortable trying. He pushes Derek down—Derek's always on his back, now—and takes control. It's abnormal. It's not like Stiles.

Derek knows something's wrong.

Every so often, Stiles will blink and there's just a flash of black. Derek isn't sure, because he's never seen anything like it and he's not sure what it _could_ be, but he knows his wolf eyes don't lie. Stiles' eyes go completely black, as though there isn't anything but inky nothingness. Derek doesn't know where to look for answers, but Stiles is starting to smell different. Derek can't place the scent, but he knows it's something he's smelled before. It's so familiar, but he just can't figure it out.

When one day Stiles sends a hunter flying, Derek is suspicious. Not because Stiles is weak—Stiles is more than strong enough to send an averagely-built man to the ground—but because Stiles tossed that hunter in the air _without touching him._ Stiles was twenty feet away when he lifted an arm and the hunter went hurtling into a tree. Pinned against the bark, his feet at least a meter above the forest floor, Stiles twists his hand, eyes narrowed at the man. A crack resounds in the bleak early morning as the hunter's neck snaps. 

Stiles has now killed three people. Before this past month, Stiles wouldn't have even gone near a gun. He'd shot a hunter to death two weeks ago, emptying round after round into the already-dead body of a young man until Derek forcibly tore the gun from his hands. Last week, Stiles strangled and stabbed a second hunter, this time female and barely out of her twenties. After squeezing her throat with his bare hands for long enough that her breath faded, Stiles pulled away and punched her into consciousness. Then, he stabbed her. He'd buried the knife so far into her ribs that the hilt was twisted into her flesh and the handle was almost halfway inside. Stiles left the knife inside her, only to take _her_ knife and slash at her torso to extricate his own blade from her body.

Stiles had always joked about letting people die, but he would always put himself in danger to save others, hunter or not. Seeing Stiles brutally kill those attackers had been disturbing, unsettling and _wrong_. Hearing the sharp sound of a third death at Stiles' hands pushes Derek into action. This man is not the Stiles he knows. This man is not the mate he loves. 

Derek stares at Stiles, then at the dead hunter. The others are not here, this time. It's only the two of them, now, and Derek wants answers. "I need you to tell me what's been going on with you," he says, approaching Stiles quickly. "You're _different_ now."

Stiles laughs, flicking his wrist. The dead hunter's corpse crumples to the ground. "You know, I thought choosing the innocent kid with the army of little fucked-up friends and an attentive, possessive boyfriend would be fun. You took this long to figure out something was wrong? That _seriously_ ruined my party." Stiles' voice is smooth and devious, and it makes Derek's nose twitch. There's that scent again, and Derek frowns as he identifies it. It's sulfur. He looks back at Stiles, his eyebrows starting to come together into a scowl. Stiles steps closer to Derek with a giddy sneer on his face that is completely unlike the goofy grins that Derek once treasured. "See," he continues, "I could have chosen anybody. Even you. Trapping _this_ little moron inside his own head, though..." He tilts his head to the side, chuckling. "That was much more fun than you ever could have been. Even now, he's beating against the walls of his little cage. He's crying for you, you know."

Derek clenches his hands into tight fists, his eyes flashing red for a brief moment. "What are you talking about?!"

Stiles raises an eyebrow. "Did your precious family teach you nothing about this world before they all sizzled to death? Honestly?" He closes his eyes, and when he opens them again, they are pure black. "Werewolves aren't the only things under the bed at night," he hisses, biting his lip and grinning even _wider_. Derek steps back, eyes wide. It's been a very long time since a taunt about his family could affect him, but hearing Stiles say it—watching Stiles' body say it, regardless of whomever has stolen his mate—is horrifying.

"Who _are_ you? I'll kill you for hurting him," Derek snarls. He doesn't shift, but his eyes glow red. 

Stiles giggles delightedly, scratching his forehead. "See, that's the best part, sweetie. You can't even touch me. I'm in your beloved mate's body. You wouldn't hurt Stiles any more than you'd turn yourself in to the Argents." His sickening black eyes bore into Derek's. It feels like a stab wound that won't heal. Derek shudders, but the thing that has taken Stiles' body continues. "Mm, I wish you could hear him now. He's begging me to spare you. He's absolutely delectable. Completely insane with trying to protect you. Oh, look at that. That was just _lovely_." Stiles walks up to Derek, who is positively shaking with fury and restraint. He can't even consider striking Stiles' body, no matter who's inside him. "Do you know what he just said? Hm?"

Derek closes his eyes, digging his claws into the flesh of his palms so he won't do anything that might harm Stiles. He doesn't know what may happen to Stiles if he doesn't go along with this, so he rasps grudgingly, "No."

Stiles' warm hands curl around Derek's wrists, and he stands on his tiptoes to press his mouth against Derek's ear. "He offered me permanent use of this body if I let you go. Isn't that sweet? Even when he can't do anything out here, he'd give up his entire life for you." Derek can feel Stiles' mouth curl into a wide grin against his cheekbone. "I really do enjoy this body, and I can't very well be impolite and decline his request. I'm sure we'll meet again, Derek Hale."

Derek shifts before he can help himself, roaring and clawing at whatever is in front of him, seeing nothing before him but red. Soon enough, he realizes that he is completely alone in the forest. His heavy breaths are the only sound for miles around. Stiles is gone, along with whatever took his body away. Instead of Stiles' warm, comforting smell that Derek had felt even when Stiles had changed, there is the pungent odor of sulfur.


End file.
